The invention is related to a balance based on the principle of the electromagnetic compensation of force having a balance scale and a balance scale carrier. The balance scale carrier can move vertically, e.g. by means of two rods of a parallel guide and is connected to a support part integral with the housing. Stops limited the movement of the balance scale carrier in a vertical direction with. A permanent magnet, and a current-carrying coil, which is located in the air gap of the permanent magnet, generate a weight-proportional counterforce. A control circuit regulates the current through the coil by a digital signal processing unit.
Balances of this type are well known. There are variations in which the control circuit permits a load-dependent direct current to flow through the coil, as is described, for example, in DE-GM 82 30 865.9, and also variations in which the control circuit sends high-frequency current impulses with load-dependent width or with load-dependent repetition rate through the coil, as is described, for example, in DE-PS 11 94 167.
A disadvantage of these known constructions is the fact that the current flow through the coil heats up the measuring system, which is particularly noticeable under rather heavy loads. This heating limits the counterforce which can be electrically generated at a given size of the permanent magnet.
Furthermore, DE-OS 20 38 214 teaches that a suspended balance scale can be set on a scale brake by briefly weakening the compensation current in order to stop an oscillation of the balance scale. This measure, introduced to dampen oscillation, does not result in any appreciable reduction of the electric stray power; in addition, a false weight is displayed during the braking of the scales. This invention has the task of reducing the electric stray power of the force-compensating system at the same carrying force and to increase the carrying force at the same electric stray power.